We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-04 · 7 min read · Independent comparison
If you want a wired, closed-back studio headphone with a neutral, controlled sound and real isolation for tracking, choose Focal Listen Professional; if you need one headphone that can switch between a closed and a semi-open presentation, choose PHONON SMB-01L.
• Focal Listen Professional — biggest strength: a closed-back, over-ear design built around precision and neutrality, with a Mylar/titanium-alloy dome driver tuned for a claimed flat response past 40kHz and very low distortion.
• Focal Listen Professional — biggest trade-off: it commits to one acoustic character (closed-back, isolation-first), so you don't get an open or semi-open alternative in the same unit.
• PHONON SMB-01L — biggest strength: interchangeable ear plates let the same headphone run as a closed-back or a semi-open design, and the 50mm driver targets deep, controlled bass with a flat low-mid response.
• PHONON SMB-01L — biggest trade-off: the semi-open plates trade isolation for a more spacious feel, so for loud tracking environments you'd want to stay in the closed configuration.
• Who each is for: Focal Listen Professional suits engineers and producers who want one dependable closed-back tool for tracking, editing and travel; PHONON SMB-01L suits engineers who want two reference "flavors" from a single Japanese-made flagship.
The Listen Professional is a circum-aural, closed-back headphone, and everything about the design points at control. Focal describes it as a tool for giving sound engineers total control over their work, whether in the studio or on a business trip — and the spec sheet backs up that framing. The driver uses a 100% Mylar suspension with a central dome made from a Mylar-titanium alloy, which adds rigidity and extends the response at the top end. Because that moving assembly is very light, Focal states the transducer can exceed 40kHz on a flat baffle.
Down low, the interesting number is distortion: Focal cites 0.3% at 1kHz – 100dB while pushing the tuning frequency as low as possible. That combination — low tuning frequency plus low distortion — is exactly what you want if your job involves judging bass and sub-bass content rather than just enjoying it. The claimed frequency range is 5Hz to 22kHz with a 40mm dynamic driver and 8 ohm impedance.
Who should buy it: producers, mix engineers and audio students who want a single closed-back reference headphone with a neutral, low-distortion character and enough isolation to work anywhere. Who should skip it: anyone who wants to alternate between closed and open presentations from one pair, or who needs a wireless-first headphone. Yes, the connectivity field lists Bluetooth 5, but the core identity here is a wired 3.5mm studio tool, so treat it as a wired headphone that happens to carry a Bluetooth spec.
PHONON SMB-01L: Who It's For
The SMB-01L is PHONON's flagship studio-monitoring headphone, made in Japan, and its whole reason for existing is versatility. The headline feature is the interchangeable ear plates: fit the closed plates and you get a fast, dense sound with the isolation you'd expect from a closed dynamic design; swap to the semi-open plates and the presentation opens up with a sense of liberation. One unit, two reference characters.
The driver is a 50mm dynamic unit with a powerful magnetic circuit and a diaphragm using a "free edge" structure. PHONON's argument is that this improves reproduction of raw sound, increases presence, and delivers a wide, high-resolution dynamic range. Bigger drivers usually boost bass at the expense of treble, but PHONON claims its tuning method keeps an acoustic balance closer to a large high-end audio system. The driver units are pitched as setting a flatness standard for mid to low frequencies with significantly low distortion — which is the language of bass monitoring, and that's clearly the intent here.
The rest of the package is built for long sessions and serviceability. You get a detachable 4-core LR cable with independent ground connection, so a damaged cable is a swap rather than a repair, and premium sheepskin ear pads for comfort. Impedance is 32 ohm and the stated frequency range is 20Hz to 20,000Hz, with a 3.5mm jack and wired connectivity only. The headphone itself weighs 343g.
Who should buy it: engineers and critical listeners who want a Japanese-made flagship with genuine bass-monitoring focus and the flexibility to move between a closed and a semi-open reference without buying a second pair. Who should skip it: anyone who needs maximum isolation at all times, or who wants wireless convenience — there's no Bluetooth here, and the semi-open configuration deliberately lets sound in and out.
• Best for isolation while tracking → Focal Listen Professional. Closed-back by design, with isolation called out as a core feature.
• Best for switching between two reference characters → PHONON SMB-01L. The interchangeable closed and semi-open plates are the entire point.
• Best for deep bass monitoring → PHONON SMB-01L. The 50mm driver is explicitly tuned to enhance natural ultra-low range monitoring.
• Best for low measured distortion in the midrange → Focal Listen Professional. Focal cites 0.3% at 1kHz – 100dB, a concrete, specific figure.
• Best for portability → Focal Listen Professional. The compact, rigid carrying case is included, and the package is built around working away from the studio.
• Best for cable longevity and comfort over long sessions → PHONON SMB-01L. Detachable 4-core cable plus sheepskin ear pads.
• Best for high-impedance-friendly sources → PHONON SMB-01L. At 32 ohm it's a more conventional load than the Focal's 8 ohm rating.
• Best for extended top-end reach → Focal Listen Professional. Claimed response reaches past 40kHz versus the PHONON's stated 20kHz ceiling.
• Best for buyers who want one headphone, not a collection → PHONON SMB-01L. Two configurations in one unit covers more ground.
In my opinion, the PHONON SMB-01L is the more interesting buy for most people reading this comparison. The switchable closed/semi-open plates, the 50mm bass-focused driver, the detachable cable and the sheepskin pads add up to a headphone that adapts to more jobs — and that flexibility is worth a lot when you're only buying one pair. I'd pick the Focal Listen Professional instead if your work is tracking-heavy and isolation plus a neutral, low-distortion closed-back reference is the priority, because that's precisely what it's built for. Both are wired studio tools; the deciding question is whether you value a single fixed reference (Focal) or two references in one unit (PHONON). Check the current price on Amazon before you commit, since that's the one variable I can't speak to here.
For mixing, it depends on what you need to hear. The Focal's closed-back design and cited 0.3% distortion at 1kHz – 100dB make it a strong neutral reference, while the PHONON's semi-open option gives a more spacious presentation. Many engineers would use the Focal as the constant and the PHONON for a second opinion.
In the closed configuration, yes — the closed plates are designed for a fast, dense sound with normal closed-back isolation. Switch to the semi-open plates and isolation drops noticeably, which is the trade-off for the more open, liberated sound.
The spec sheet lists Bluetooth 5 in the connectivity fields, but the headphone's identity is a wired 3.5mm closed-back studio tool with a 40mm driver and 8 ohm impedance. If you're buying it for wireless listening, verify that use case against the listing first.
The PHONON SMB-01L is described with premium sheepskin ear pads and weighs 343g, which is a reasonable figure for a flagship over-ear. The Focal Listen Professional emphasizes optimal comfort and sized ear cushions, and ships with a rigid case. Neither spec sheet gives a decisive edge, so fit will come down to your head and ears.
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